» Sat Feb 19, 2011 1:45 am
Nope. Lowers H2O meter, restores health. Exactly the same as any purified water.
No Cactus Water item in the GECK, either.
edit: A little research indicates that the 360 version may have a bugged recipe for "Cactus Water" which indicates it's something different from Purified Water, but there is no ingestible named "Cactus Water" in the GECK.
They seem to be identical in my game, so it might have been fixed in the last "incremental patch"